Upper Black Creek Constructed Wetland: Pre-Construction Monitoring

More than half of the Mona Lake watershed is developed or in agricultural production, threatening the water quality of Mona Lake and its tributaries. Two tributaries in the watershed have impaired biological communities - Black Creek and Little Black Creek. Water quality concerns in the watershed include 1) hypereutrophic condition of Mona Lake and nuisance algal blooms resulting from high phosphorus loadings, 2) severe chemical and biological degradation of Black Creek and Little Black Creek, and 3) high levels of pathogens during storm events.

The Mona Lake Watershed Management Plan, developed by the Mona Lake Watershed Council (MLWC), identified the sources and causes of the known and suspected pollutants in the watershed and proposed systems of best management practices (BMPs) to address nonpoint source pollution. This project addresses a proposed constructed wetland that was identified as a high priority project in the plan.

Our task is to conduct pre-construction monitoring to facilitate wetland design development and generate baseline data to validate future in-stream water quality improvements. This will be achieved through the following objectives:

Characterize water quality during both wet and dry conditions Measure flow, determine rating curves, and generate a hydrograph Describe soil chemistry and phosphorus biogeochemistry of proposed wetland area Characterize the geomorphology of the stream channel Survey the fish community

Once constructed, the wetland will result in regional secondary treatment for 20 square miles of agricultural runoff, estimated to reduce sediment to Black Creek and Mona Lake by 6 tons/year and nutrients by 1,005 lbs P/year. Our monitoring work will set the stage for the creation of the wetland.

Funding for this project was provided by the Michigan Department of Environmental Quality. Our project partner is the Mona Lake Watershed Council.